The Maine Center for Disease Control and Prevention and the Maine Department of Agriculture said Monday that the discovery of EEE in another 13 mosquito pools brings the total to 21, with mosquitoes testing positive in the York County towns of Alfred, Kittery and York. Another mosquito pool tested positive for West Nile Virus.

Both West Nile and EEE can be transmitted to humans through the bite of an infected mosquito.

Last week, two horses died from EEE in Oxford and York counties, and pheasant died from EEE in York County. Health officials are urging people to take steps to avoid mosquito bites.